Atheist professor Richard Dawkins has sparked a storm of controversy online for suggesting a Muslim journalist should not have had an opinion piece published, claiming his Islamic beliefs in a winged horse mean he is not "a serious journalist".

The comment was directed at Mehdi Hasan, political director of The Huffington Post UK, who was challenged by Dawkins in an interview last year to admit he believed the Prophet Mohammed flew to heaven on a winged horse.

The piece was published in December 2012 but Dawkins only tweeted his response this Sunday, saying: